Adjustable dumbbell and kettlebell structures

ABSTRACT

A weight-lifting device having a shaft; at least one pair of weight plates, and a securing means. The at least one pair of weight plates are suitable to be connected to the shaft. At least one of the weights is provided with a recessed portion suitable to house the shaft or part thereof. The securing means are suitable to hold the pair of weights in close positioned relationship with one another and with the shaft when in a packed position.

FIELD OF THE INVENTION

The present invention relates to the field of weight lifting devices. More particularly, the invention refers to adjustable types of weights that are used in physical training exercises, such as dumbbells and/or kettlebells and/or medicine balls.

BACKGROUND OF THE INVENTION

Weight lifting requires an individual adjustment of training programs for each person, when taking into consideration different personal factors such as age, sex, weight, level of fitness, and final workout goals.

Several people can use the same dumbbell, but each of them has to adjust the weight of the dumbbell according to his personal factors. Even when a dumbbell is for personal use, it needs to be adjustable since over time, as the training proceeds, the personal factors are likely to change, and the weight of the dumbbell should be adjusted accordingly. In addition, the weight of weight-lifting devices needs to be adjusted according to each specific exercise.

Most adjustable dumbbells can be adjusted by positioning a number of weights, one beside the other, thus causing a change in the length of the dumbbell that increases the moment on the shaft, which, in turn, can be unhealthy for the joints and muscles and forces the trainee to find new balance with each adjustment.

When traveling, a dumbbell can be very hard to carry, and it usually requires placing each weight separately and also apart from the shaft, all of which need to be stored in a relatively large compartment, or even in several different compartments.

Therefore, it is an object of the present invention to provide an adjustable dumbbell, the weight adjustment of which by the addition of weights will not increase its length.

It is another object of the invention to provide a device and a method that will provide a fast and easy dismantling and assembly thereof.

It is a further object of the present invention to provide a device that can be easily packed and carried.

Other objects and advantages of the invention will become apparent as the description proceeds.

SUMMARY OF THE INVENTION

The invention relates to a weight-lifting device, which is also referred to as a dumbbell, comprising: a shaft, at least one pair of weights that are suitable to be connected to said shaft, wherein at least one of said weights is provided with a recessed portion suitable to house the shaft or part thereof; and securing means that are suitable to hold said pair of weights in close positioned relationship with one another and with the shaft when in packed position.

The device can comprise weights that are suitable to be housed within another weight of different size and/or shape. The housing of weights one within the other can be performed when assembling the dumbbell and when packing it. Different weights can be made of different materials, to provide weight differences by using materials with different specific weight.

The shaft can be an adjustable shaft in order to control its length, so it can fit different conditions, such as different people who use the same device and/or different training exercises. The securing means are suitable to keep adjacent weights in close positioned relationship, for example, in a packed position wherein the largest pair of weights covers the shaft. The securing means are also suitable to connect to the edges of the shaft, thus securing the connection of the weights to the shaft. The edges of the shaft can be shaped as a screw, and the securing means are shaped accordingly, to be able to connect to the shaft.

At least two weights are provided with openings that allow the device to be suitable for easy grip since they provide the shape of a handle and the user can carry the device as he would carry a suitcase. The shape of the device in a packed position is also suitable for exercises that require a kettlebell weight, which is a known type of fitness device/equipment, used in various weight-lifting exercise forms. The device can further comprise a stopping mechanism that prevents the weights from moving along the shaft.

The securing means can comprise knobs and male/female edges. The shaft can comprise surrounding parts, suitable, together with the knobs of the securing means, to allow setting the distance between two sets of weights of the dumbbell structure in its assembled position. The shaft can further comprise a rough texture at its surface for a comfortable grip, and a screw thread, suitable to be coupled to a securing component, which is of the shape of a screw.

The surface of the weights can comprise grooves, or any other component that will limit the movement and/or rotation of two weights that are in contact. The weights of the device can be further provided with a compartment, which acts as a storage space for the shaft and other accessories to the dumbbell.

The device can also be used as a kettlebell and can further comprise a kettlebell handle and/or a double kettlebell handle.

According to an embodiment of the invention, the securing means are an integrated part of each weight plate.

According to an embodiment of the invention, the securing means comprise a ledge and a recessed portion.

According to an embodiment of the invention, the securing means comprise a retractable restricting element and a trigger suitable to retract said restricting element.

According to an embodiment of the invention, the securing means of a first weight are suitable to be connected to the securing means of a second weight or to the shaft.

According to an embodiment of the invention, the device further comprises a kettlebell to which a plurality of interconnected weight plates can be attached on each side of said kettlebell.

According to an embodiment of the invention, the kettlebell comprises a storage space for the shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further illustrated with reference to the appended drawings, wherein:

FIG. 1 is a side view of the device, according to one embodiment of the invention, showing the weights in a dismantled position;

FIG. 2 is a perspective view of the device of FIG. 1, in which the weights are in contact with one another;

FIG. 3 is a perspective view of the device of FIG. 1, in which only the large weights and the small weights are connected to the shaft;

FIG. 4 is a perspective view of the device of FIG. 1, where only the middle weights and the small weights are connected to the shaft;

FIG. 5 is a perspective view of the device of FIG. 1, illustrating the packing process of one side of the device;

FIG. 6 is a perspective view of the device of FIG. 1, illustrating the packing process, where the weights are housed one within the other;

FIG. 7 is a perspective view of the device of FIG. 1 in a packed position, where both large weights are in contact with the shaft; and

FIG. 8 is a front view of the device of FIG. 1, showing the device in a packed position;

FIG. 9 is a perspective view of the device, according to a second embodiment of the invention, showing the weights in a packed position;

FIG. 10 is a perspective view of the securing component of the device of FIG. 9;

FIG. 11 is a front view of the middle weight plate of the device of FIG. 9;

FIG. 12 is a perspective view of the shaft of the device of FIG. 9;

FIG. 13 is a perspective view of the device of FIG. 9, when the device is in an assembled position;

FIG. 14 is a perspective view of the device of FIG. 9 when the device is in an assembled position and only 4 weight plates are in use:

FIG. 15 is a perspective view of the device of FIG. 9 when the device is in an assembled position and only 2 weight plates are in use:

FIG. 16 is a front view of the device of FIG. 13;

FIG. 17 is a perspective view of a kettlebell handle;

FIG. 18 is a side view of a set of weights, when a kettlebell handle is placed in the storage chamber on top of them;

FIG. 19 is a top view of the device of FIG. 18, with a securing component placed in the storage chamber;

FIG. 20 is a side view of the device of FIG. 9, where a kettlebell handle is connected to two full sets of weight plates;

FIG. 21 is a side view of the device of FIG. 9, where a kettlebell handle is connected to 2 weight plates on each side;

FIG. 22 is a side view of the device of FIG. 9, where a kettlebell handle is connected to a single weight plate on each side;

FIG. 23 is a perspective view of a double kettlebell handle;

FIG. 24 is a front view of the device of FIG. 9, where a double kettlebell handle is connected to two full sets of weights;

FIG. 25A is a perspective view of securing means suitable to be an integrated part of a weight plate, according to an embodiment of the invention;

FIG. 25B is an exploded view of the securing means of FIG. 25A;

FIG. 26 is a perspective view of a shaft, according to an embodiment of the invention;

FIG. 27 is a perspective view of a weight plate according to an embodiment of the invention, with a securing element;

FIG. 28 shows a device comprising a plurality of interconnected weight plates attached on each side of a kettlebell;

FIG. 29 is a perspective view of the device, according to another embodiment of the invention;

FIG. 30A shows a perspective view of a kettlebell device according to an embodiment of the invention;

FIG. 30B shows a side cutaway view of the kettlebell device of FIG. 30A;

FIG. 31A shows a perspective view of a kettlebell device according to yet another embodiment of the invention; and

FIG. 31B shows a side cutaway vie of the kettlebell device of FIG. 31B.

DETAILED DESCRIPTION OF THE INVENTION

The device of the invention comprises a shaft, weight plates, and mechanical connection means that together form an adjustable dumbbell. A dumbbell should be weight adjustable to fit different personal factors of several people, or to fit the same person along a period of time, or even to fit different workouts of the same person according to his needs on different occasions. In any event, it is very important that the weight of dumbbells be suitable for the trainee at all times, since the lifting of excessive weight can cause injuries, pain, and long term damages, and the use of a lighter weight than recommended is not the most efficient.

FIG. 1 is a side view of the device, according to one embodiment of the invention, showing the weight plates in a dismantled position, where shaft 101 is connected to one pair of weight plates—large weight plates 102 a and 102 b. This view also shows two other pairs of weight plates—middle weight plates 103 a and 103 b and small weight plates 104 a and 104 b, when they are separate from shaft 101 and from large weight plates 102 a and 102 b, thus showing the size differences between them, when they are apart.

Each weight plate is suitable to be connected to shaft 101 separately, and each weight plate is suitable to be housed inside a larger weight plate, for example, small weight plate 104 a can be housed inside middle weight plate 103 a or inside large weight plate 102 a. The device can comprise more than three sizes of weight plates, and each weight plate can be housed inside a larger one, as will be illustrated over the following figures.

According to the embodiment of FIG. 1, the different pairs of weight plates are of different sizes, thus allowing one pair to house the other, but the difference can also be, according to another embodiment of the invention, in the shape of both pairs that will allow the combination of the two pairs, even if the sizes are very similar. Moreover, different materials, having different specific weight, can be used to provide desired weight difference between different weight plates.

The maximal length of the device is the sum of the length of shaft 101 and the length of the two large weight plates 102 a and 102 b, and any other weight plate is designed to be housed within a larger weight plate without exceeding that length, as shown in FIG. 1, where length A of large weight plate 102 a is larger than length B of middle weight plate 103 a, and length B of middle weight plate 103 a is larger than length C of small weight plate 104 a.

The length of shaft 101 can be adjustable (telescopically for example), which is useful when several people use the same device, or when the user wishes to perform different types of exercises. Shaft 101 also comprises a stopping mechanism, such as stopping mechanism 105, which prevents the weight plates from moving along its length. The stopping mechanism can be a rigid part of shaft 101, but it can also be a separate part that can move along shaft 101 and be fixed at a position along shaft 101 by the user, according to the number of weight plates, their dimensions, the exercise, etc.

FIG. 2 is a perspective view of the device of FIG. 1, in which small weight plate 104 a is housed within middle weight plate 103 a, which, in turn, is housed within large weight plate 102 a. Each weight plate can be connected independently to shaft 101 by any mechanical means, like screws or clips. Another option for connecting the weight plates to shaft 101 is to connect the largest weight plate that the user wishes to use to shaft 101 and then place the other smaller weight plate in position and use securing means, such as securing component 201, to prevent any movement between the weight plates.

Weight plates 102 a and 102 b are provided with dents along their circumference, which prevent the device from rolling when a user puts it on the floor, and also allows to use the device in different training exercises that require the use of the device when it is located on the floor, without the risk of rolling, for example, a “push-up” exercise in which the user holds shaft 101 and weight plates 102 a and 102 b are in contact with the floor or with any other surface. The shapes of all weight plates can be suitable to prevent the rolling of the device when it is located on a surface, as shown in FIG. 2.

As further shown in FIG. 2, the connection between shaft 101 and the weight plates is performed by placing the weight plates between shaft 101 and securing means 201 before connecting them, which according to this embodiment is performed by inserting shaft 101 and/or securing component 201 through a central opening (601, FIG. 6) located essentially at the middle of the weight plates. Securing component 201 is suitable to be connected to shaft 101 by a screw, but it can be replaced with any other securing component, like a female-male connection, and shaft 101 can be replaced accordingly and be provided with an edge that allows the connection of shaft 101 to any securing component. The shape of all weight plates is suitable to prevent any rotational movement between the weight plates and between each weight plate and shaft 101.

As shown in FIG. 2, large weights 102 a and 102 b are provided with openings 202 a and 202 b. The purpose of openings 202 a and 202 b is to allow the carrying of the device when it is in a packed position. The process of packing the device and the advantages of openings 202 a and 202 b will be described over the following paragraphs. FIG. 2 also shows that each weight comprises two notches (501 a-501 c′, FIG. 5), which will also be described hereinafter.

FIG. 3 is a perspective front view of the device of FIG. 1, in which only large weight 102 a and small weight 104 a are connected to shaft 101 on the front side of the device, and FIG. 4 is a perspective front view of the device of FIG. 1, in which only middle weight 103 a and small weight 104 a are connected to shaft 101 on the front side of the device. Those figures show exemplary combinations of weights for the purpose of illustrating the control the user has over the weight of the dumbbell. Of course it is also possible to connect only a single weight or any combination of weights to shaft 101.

It is also shown in FIG. 3 that weight 104 a is provided with holes 301, which are suitable for easy extraction of weight 104 a when dismantling the device. Any weight can be provided with one or more holes (such as holes 301) and the holes can be positioned anywhere on the weights.

Another advantage of the invention over the prior art is the ability to pack the device. FIG. 5 is a perspective view of the device of FIG. 1, illustrating the packing process of one side of the device that includes weights 102 a, 103 a, and 104 a, and shaft 101, where each weight comprises notches (numbered as 501 a, 501 b, and 501 c). Notch 501 c has a parallel notch 501 c′ at the other side of weight 104 a. Weights 102 a and 103 a also comprise two notches, like weight 104 a (not shown in this figure). The shape and size of the notches are suitable to be coupled to shaft 101 in a packed position, as will be shown in FIGS. 6 and 7.

FIG. 5 also shows restraining means 502 that are shaped to prevent weights from rotating around shaft 101 when they are connected. Restraining means 502 are located between stopping mechanism 105 and the weights that are first connected to shaft 101 on both sides of the device. The weights of the device are suitable to be coupled to restraining means 502, and the shape of restraining means 502 is an octagon, thus preventing a rotational movement of the weights around shaft 101, but it can be replaced with any other shape that prevents said rotational movement.

Appropriate rubber or the like material may be positioned on various elements of the device of the invention, to facilitate assembly and locking when different parts are brought into contact with one another. For instance, both edges of said shaft 101 can comprise a rubber 0-ring capable of compression when force is applied thereon.

FIG. 6 is a perspective view of the device of FIG. 1, further illustrating the packing process, where weights 102 a, 103 a, and 104 a are housed one within the other, and shaft 101 is placed on top of weights 102 a, 103 a, and 104 a, in contact with the notches of the weights. Although only large weight 102 b is shown at the upper part of the figure, weight 102 b also comprises middle weight 103 b and small weight 104 b, similarly to weight 102 a. Large weight 102 b is located above shaft 101 to indicate that as the packing continues, weight 102 b will cover shaft 101, which will be located in the middle of the assembled device. FIG. 6 also shows central opening 601 through which shaft 101 and/or securing component 201 can be inserted.

FIG. 7 is a perspective view of the device of FIG. 1 in a packed position, showing the result of the step of FIG. 6, where both large weights 102 a and 102 b are in contact with shaft 101. In this packed position shaft 101 that is located between weights 102 a and 102 b is not seen, and only securing component 201 that is connected to shaft 101 is shown. Securing component 201 is shown in a packed position according to this embodiment, but it can also be hidden in the packed position, according to another embodiment of the invention in which the weights are of different sizes and/or since shaft 101 can be adjusted at its length, and the notches of the weights can be shaped accordingly in order to be suitable to house shaft 101 and/or securing means of any kind. The device can be secured in its packed position by securing component 201, as shown in FIG. 7, or by any other means that are suitable to keep large weights 102 a and 102 b in a close positioned relationship, like clips on the outer surface of large weights 102 a and 102 b.

FIG. 8 is a front view of the device of FIG. 1, in which the device is in a packed position. As mentioned in the description of FIG. 2, openings 202 a and 202 b are provided at the largest weights for comfortable carrying of the device, when it is in a packed position. Openings 202 a and 202 b are suitable for easy grip since they provide the shape of a handle to the device when it is in a packed position, and the user can carry the device as he would carry a suitcase. All of the other weights are also designed in a way that do not interfere with the shape of the handle when the device is in a packed position.

The shape of the device when it is in a packed position provides the user with the ability to utilize the device for other types of training exercises. Such exercises that usually require kettlebell weights, therefore allowing the user to achieve different types of training without additional equipment, which is simply executed and cost efficient.

In the first embodiment of the invention, shown in FIGS. 1-8, when the device is in a packed position, the larger weights are located on the outer side of the device, but the weights can also be arranged differently, for example, as shown in FIGS. 9-24, relating to the second embodiment of the invention, where the smaller weights are located on the outer side of the device.

Some parts of the second embodiment are essentially similar to the parts of the first embodiment, but since they are not identical they will be referred to as “second (name of the part)”, for ease of reference. Although the description refers to two specific embodiments, it does not mean that the invention is limited only to those two embodiments, and those only serve as two exemplary embodiments of the present invention.

FIG. 9 is a perspective view of the device, according to the second embodiment of the invention, showing the weights in a packed position. Unlike in the packed position of the embodiment in FIG. 7, second large weights 901 a and 901 b are in “back to back” contact and second middle weight 902 a is positioned inside second large weight 901 a, and second small weight 903 a is positioned inside second middle weight 902 a so that all weights are visible when the device is in a packed position. Although it is not shown in this figure, second large weight 901 b also hosts middle and small weight (902 b and 903 b) similarly to the set of weights 901 a, 902 a, and 903 a.

The device also comprises securing means, such as second securing component 904 that is shown in FIG. 9. Two securing components can be connected to each other in order to keep the two sets of weights in contact when in packed position. FIG. 10 is a perspective view of second securing component 904, which is a screw that is suitable to be coupled to each weight or to any combination of weights, and that is secured in position when the device is in a packed position, by pairing it with a compatible mate that is also coupled to a set of weights and can connect to second securing component 904. Such connection between a pair of securing components can be performed by any known connection, for example, as shown in FIG. 10, second securing component 904 is provided with a “male edge” 1001 that can be screwed into a “female edge” of a similar securing component. Weights 901 a and 901 b can further comprise additional connection means in order to keep close contact.

The size and shape of screw head 1002 of second securing component 904 are designed to provide an easy grip and rotation of second securing component 904 by a user. In addition, screw head 1002 prevents the user from inserting second securing component 904 too deep into the space that hosts it. The space that hosts second securing component 904 is in fact a continuous void created by openings that are provided in each weight, similarly to central opening 601 of the first embodiment (as shown in FIG. 6).

As shown in FIG. 11, which is a front view of second middle weight 902 a, the weights of the device can be provided with supporting legs, such as legs 1101, which are designed to support the device when it is placed on a surface and to prevent its rotation in relation to said surface. FIG. 11 shows second middle weight 902 a that comprises legs 1101 and the shape of its inner wall is suitable to host a smaller weight that also comprises legs, due to slots 1102 that are compatible in shape to the legs of a weight that can be positioned inside second middle weight 902 a.

FIG. 11 also shows the inner surface of weight 902 a that comprises grooves 1103 that can be provided in the inner surface of the weights for the purpose of enhancing the friction between two weights that are in contact, in order to prevent, or at least restrain, the movement between them. The weights can also comprise bumps on their back surface, adapted to enter the grooves that are located in the front inner surface of the larger weight, thus preventing or limiting movement between the two weights. Grooves 1103 can be replaced with any other suitable friction-enhancing mechanism, such as a rough surface.

Weight 902 a also comprises gripping holes 1104 that are provided to allow the user an easy grip of the weights when assembling and disassembling the weights of the device. As mentioned, the space that hosts second securing component 904 is a void created by openings that are provided in each weight, such as opening 1105 that is shown in FIG. 11.

FIG. 12 is a perspective view of the shaft of the device, according to the second embodiment of the invention. Second shaft 1201 is provided with a rough surface 1202 or ergonomic design that is provided for a comfortable and healthy grip of a user, and to prevent the slipping of the shaft against the hands of the user. When the device is in an assembled position, as shown in FIG. 13, second securing component 904 is inserted into the central opening of the weight plates, and second securing component 904 is connected to second shaft 1202. The same connection is performed on the other side of the device (not shown).

The connection between second securing component 904 and second shaft 1201 can be performed by any mechanical connection. For example as shown in FIG. 12, second shaft 1201 is provided with an inner screw thread 1203 suitable to be connected to second securing component 904. As shown in FIG. 10, second securing component 904 also comprises knobs 1003, which are designed to perform as stopping points. When connecting second securing component 904 to second shaft 1201, surrounding parts 1204 (shown in FIG. 12) that surround inner screw thread 1203, come in contact with knobs 1003 in order to indicate the user that he reached a stopping point. The user can then decide if he wants to proceed with the current length of the device, or if he wishes to shorten it by proceeding to the next stopping point at the following knob. In order to proceed with the screwing of second securing component 904 into second shaft 1201 after the encounter with the first knob 1003, surrounding parts 1204 can be provided with a mechanism that can pass over knobs 1003, such as inner springs that can be pressed in order to increase the distance between two surrounding parts 1204, which can be controlled by a user.

In FIG. 13 the device in its assembled position comprises three weight plates on each side 901 a, 902 a, 903 a, 901 b (and also 902 b and 903 b, not shown in this figure), but of course the device is not limited to only three weights or to any specific number of weights, and it can comprise a larger or smaller number of weights, as shown for example in FIG. 14, where only weights 902 a, 903 a, 902 b (and 903 b, which is not shown in this figure) are in use, or in FIG. 15, where only weights 903 a and 903 b are in use.

FIG. 16 is a front view of the device of FIG. 13, where second large weight 901 a is provided with on opening 1601, similar to openings 202 a and 202 b that are shown in FIG. 2. As mentioned above, the purpose of those openings is to provide the possibility of a carrying handle, which can also be helpful in different workout exercises, like kettlebell exercises.

Another way of achieving a kettlebell-shaped weight is by connecting a handle, such as kettlebell handle 1701 that is shown in FIG. 17, which is provided with the same edge parts as in second shaft 1201, which are suitable to connect to second securing component 904; those parts are handle screw thread 1702 and handle surrounding parts 1703, and they are detachable from handle 1701.

As shown in FIG. 18, handle 1701 is positioned on the back surface of weight 901 a, and handle 1701 is provided with screw thread 1702 (not shown) and handle surrounding parts 1703. When second securing component 904 is attached to the device, when the device is positioned as in FIG. 18, it can be used as a kettlebell. FIG. 19 is a top view showing half of the device of FIG. 18, after connecting second securing component 904. Second shaft 1201 can be positioned at the back surface of second large weight 901 a, at a space provided for it, so it would have a storage space when the device is in its packed position.

FIG. 20 is a side view of the device of FIG. 9, where handle 1701 is connected to two sets of weights, which provides another form of a kettlebell weight. In this figure the assembled device comprises three weights (901 a, 902 a, 903 a on one side, and 901 b, 902 b, and 903 b on the other side), but it can also comprise a larger or a smaller number of weights, as shown in FIG. 21, where only weights 902 a, 903 a, 902 b, and 903 b are in use, or in FIG. 22, where only weight 903 a and 903 are in use.

As shown in FIG. 23, handle 1701 can be replaced with double kettlebell handle 2301, to provide users the possibility to hold the device with both hands (i.e., as a medicine ball). FIG. 24 is a front view of the device of FIG. 9, where double kettlebell handle 2301 is connected to two full sets of weights.

According to another embodiment of the invention, a weight plate comprises securing means that can be actuated in order to independently attach and detach the weight plate to a shaft and to other weight plates. FIG. 25A is a perspective view of securing means 2501 suitable to be an integrated part of a weight plate, according to an embodiment of the invention. Securing means 2501 comprises ledges 2503 on each side of a protrusion 2502, and a recessed portion (not shown) on the side opposite to the protrusion. Ledges 2503 are adapted to be inserted and locked in the recessed portion of other securing means 2501. FIG. 25B is an exploded view of an exemplary embodiment of securing means 2501. In this embodiment securing means 2501 consist of the following elements: a first layer 2501 a that includes protrusion 2502 and ledges 2503; a second layer 2501 b for receiving the protrusion 2502 of another securing element 2501; and a spring locking mechanism in a third layer including elements 2501 c and 2501 d; and a ledge insertion layer 2501 e through which the protrusion of another securing means 2501 can be inserted or extracted only in some orientations of its ledges 2503.

According to another embodiment of the invention, the securing means can be implemented in a variety of ways as will be appreciated by a person skilled in the art. For instance an embodiment of the securing means comprises a retractable restricting element and a trigger suitable to retract said restricting element (not shown).

FIG. 26 is a perspective view of a shaft 2601 with fixed ledges 2602 at the periphery of each end, according to an embodiment of the invention. Shaft 2601 can be attached to securing element 2501, when inserted to the recessed portion in securing element 2501.

FIG. 27 is a perspective view of weight plate 2701, at the center of which is a securing element 2501. Accordingly, and as explained hereinabove, weight plate 2701 can be reversibly attached to a shaft 2601 without the use of additional securing elements, such as securing means 201 and as illustrated in other embodiments.

According to an embodiment of the invention, a protrusion 2502 of a first securing element 2501 can be inserted to the recessed portion of a second securing element 2501 in order to attach the first securing element to the second. Accordingly, two or more weight plates, each provided with securing elements 2501, can be attached to each other in order to, for instance, increase the overall weight of a dumbbell or a kettlebell or to obtain a packed position of the device. FIG. 28 shows a device 2801 comprising a plurality of interconnected weight plates 2701 attached on each side of a weight plate in form of a kettlebell 2803. According to an embodiment of the invention, kettlebell 2803 comprises a storage space for shaft 2601.

FIG. 29 is a perspective view of the device, according to another embodiment of the invention, showing weight plates connected to each other in a dumbbell form, in which small weight plate 2701 a is housed within middle weight plate 2701 b, which, in turn, is housed within large weight plate 2701 c.

Each weight plate is suitable to be connected to shaft 2601 separately, and each weight plate is suitable to be housed inside a larger weight plate, for example, small weight plate 2701 a can be housed inside middle weight plate 2701 b or inside large weight plate 2701 c. The device can comprise more than three sizes of weight plates.

According to the embodiment of FIG. 29, the different pairs of weight plates are of different sizes, thus allowing one pair to house the other, but the difference can also be, according to another embodiment of the invention, in the shape of both pairs that will allow the combination of the two pairs, even if the sizes are very similar. Moreover, different materials, having different specific weight, can be used to provide desired weight difference between different weight plates.

FIG. 30A shows a perspective view of a kettlebell device 3001 according to an embodiment of the invention, with securing means 2501, and two storage openings 3002 into which a shaft (e.g. numeral 2601 in FIG. 26) may be inserted. FIG. 30B shows a side cutaway view of the kettlebell device 3001 of FIG. 30A, provided with a core weight 3003. FIG. 31A shows a perspective view of a kettlebell device 3101 according to yet another embodiment of the invention, with securing means 2501 and a storage opening into which a shaft ( e.g. numeral 2601 in FIG. 26) may be inserted. FIG. 31B shows a side cutaway of the kettlebell device 3101 of FIG. 31B, provided with a core weight 3103.

According to an embodiment of the invention, the device's elements such as the weight plates and the kettlebell device may include a protective rubber coating. For example, core weight 3003 of kettlebell device 3001 may include such as a protective rubber coating.

According to the packing method of the invention, the usage of space is essentially optimized because there is almost no void between the components when the device is in a packing position. In addition, all of the components of the device are packed together; unlike in other devices where not all of the components can be connected when packed and/or other additional components need to be used for packing and/or carrying.

All the above description has been provided for the purpose of illustration and is not meant to limit the invention in any way. 

1. A weight-lifting device comprising: a) a shaft; b) at least one pair of weight plates that are suitable to be connected to said shaft, wherein at least one of said weights is provided with a recessed portion suitable to house the shaft or part thereof; and c) securing means that are suitable to hold said pair of weights in close positioned relationship with one another and with the shaft when in packed position.
 2. The device according to claim 1, comprising weights suitable to be housed within another weight of different size and/or shape.
 3. The device according to claim 1, wherein the length of the shaft is adjustable.
 4. The device according to claim 1, wherein the securing means are suitable to keep adjacent weights in close positioned relationship.
 5. The device according to claim 1, wherein the securing means are suitable to connect to the edges of the shaft.
 6. The device according to claim 1, wherein the edges of the shaft are shaped as a screw.
 7. The device according to claim 1, wherein at least two weights are provided with openings.
 8. The device according to claim 1, wherein different weights are made of different materials.
 9. The device according to claim 1, further comprising a stopping mechanism.
 10. The device according to claim 1, wherein the securing means comprise knobs.
 11. The device according to claim 1, wherein the securing means comprise male/female edges.
 12. The device according to claim 1, wherein the surface of the weights comprises grooves.
 13. The device according to claim 1, wherein the shaft comprises a rough texture.
 14. The device according to claim 1, wherein the shaft comprises a screw thread.
 15. The device according to claim 10, wherein the shaft comprises surrounding parts, suitable, together with the knobs, to allow setting the distance between two sets of weights of the dumbbell structure in its assembled position.
 16. The device according to claim 1, further comprising a kettlebell handle.
 17. The device according to claim 1, further comprising a double kettlebell handle.
 18. The device according to claim 1, wherein at least one of the weights comprises a storage space for the shaft.
 19. The device according to claim 1, wherein the securing means are an integrated part of the weight plates.
 20. The device according to claim 19, wherein the securing means comprise a protrusion, a ledge and a recessed portion.
 21. The device according to claim 19, wherein the securing means of a first weight plate are suitable to be connected to the securing means of a second weight plate or to the shaft.
 22. The device according to claim 1, further comprising a kettlebell to which a plurality of interconnected weight plates can be attached on each side of said kettlebell.
 23. The device according to claim 22, wherein the kettlebell comprises a storage space for the shaft. 